Production and Physiological Characters of Soybean under Drought Stress with Foliar Application of Exogenous Antioxidant
Yaya Hasanah, Lisa Mawarni, Teuku Irmansyah
University of Sumatera Utara, Fac. of Agriculture, Indonesia
Climate change is a serious threat to the agricultural sector, and it is one of the causes of drought affecting growth and development of plants. Soybean is one of the main food protein sources in Indonesia, and drought stress may affect its production considerably. Drought stress changes physiological and biochemical aspects of plant leading to cell damage due to oxidative stress caused by increased free radical accumulation in the form of reactive oxygen species. One approach for improving the tolerance of oxidative stress in soybean under drought stress is the application of exogenous antioxidants. The aim of this research was to investigate the effect of foliar application of exogenous antioxidant on production and physiological characters of soybean under drought stress. In a factorial randomised block design two factors were studied with three replications. The first factor was drought stress with three treatments: plant watering till 80%, 60% and 40% field capacity. The second factor was foliar application of exogenous antioxidant with five treatments: no foliar application (control) or an application with salycilic acid (500 ppm), ascorbic acid (500 ppm), α-tocopherol (500 ppm) or chitosan (500 ppm). The results suggest that increased drought stress conditions caused decreasing of stomatal density, total leaf chlorophyll, total leaf area, relative water content, number of filled pods, and 100 seeds weight. The effect of ascorbic acid as an exogenous antioxidant increased the total chlorophyll content of the leaves, total leaf area, number of filled pods, and relative water content, while chitosan treatment increased stomatal density only. Overall, exogenous antioxidants reduced the effects of water stress on production and physiological characters of soybean.
Keywords: Antioxidant exogenous, drought stress, foliar application, soybean
Contact Address: Yaya Hasanah, University of Sumatera Utara, Fac. of Agriculture, Jl. Prof. A. Sofyan No 3 Kampus USU, 20155 Medan, Indonesia, e-mail: yayausu.ac.id